Heat insulating panel member



April 25 1933 R. T. GRIFFITHs 1,905,853

HEAT INSULATING PANEL MEMBER 4,a 4 4 1 3. 4 4b 4a lb Filed Dec. 2o, 1929v 4 sheets-sheet 1 2\ 2` 2lb "la gm b2 R. T. GRIFFITHS 1,905,853

'HEAT INSULATING PANEL MEMBER Aprilzs, 1933. 1

Filed Dec. 2o, 1929 4 Sheets-sheet 2 In uei'or.- Hicham Izar/Wim R. T. GRIFFITHS 1,905,853

HEAT INSULATING PANEL MEMBER Filed Deo. 2o, 1929 4 sheets-sheet s AprilY 25, 1933.

l Richard Gayiifhs, By /m Inu April' 25, 1933. j R T. GRIFFITHS 1,905,853

HEAT INSULATING PANEL MEMBER Filed Dec. -zo, 1929 4 sheets-sheet 4' /E /LV 1 b 14# 6] 11 14 l t 1 7 17 1@ 1@ l nueni'or: Rich and TGIWIIZ'M',

Patented Apr. 2s, 1933 UNITED STATE-s PATENT" ormc i nIonAnn 'I'. Gamme., or AKRON, OHIO, AssIGNomBY- mEsNE ASSIGNMENTS, To mma RUBBER COMPANY INO., or WILMINGTON, DELAWARE, A coaronA'rIoN OF DELAWARE HEAT INSULATING PANEL Application mea recenter 20, 192e. serial No. 415,541.

My presentinvention concerns an improvement in panels, doors, or closure members for refrigerator structures and a method of making the same. While the invention is vdesigned primarily for use in connection with the so-called iceless metal refrigerators which have come so extensively into use of late, and

are usually made more or less of metal, it is Y obviously not limited to such use but is applicable to any type of container structure which is designed to insulate the contents from thewarmth of the surrounding atmosphereA or vice versa.

For convenience in illustrating and describing the invention, I have chosen for its embodiment a refrigerator door, but it will be understood that this is by way of example quent chilling of the outside, which, in a warm, humid atmosphere causes excessive sweating,

moisture in the atmosphere condensing on the outside walls and dripping onto the .Hoor and producing disagreeable results, besides detracting from the efficiency of the refrigerator or cooler. The present invention aims to avoid these results and to provide a door or panel structure having metal inside and outside walls which will be eifectively united in a manner to reduce he conduction to an absolute minimum; to provide an article and method of making the same which will result in extreme economy in production, and one in which the resulting article will be extremely durable in use and will be free from bolts, screws, rivets and the like for connecting the metal parts together. l y

With these and other objects in view, which will hereinater'appear, the invention includes the novel article and method of making the same hereinafter described and defined by the appended claims.

In the accompanying drawings:

-Figure 1 is a transverse sectionthrough a mold such as vmay be used for forming one of the units of a panel member of a refrigerator or like structure, such for example as a refrigerator part or door, tank closure a0 or cover of the type used for storage of ice cream, arefrigerator door being selectedlfor purposes of illustration, such unit being shown in place in the mold, said ligure being partly broken away.

v Fig. 1a is a similar view illustrating a modilied method of procedure.

Fig. 1b is a similar view showing a method of procedure as modified to produce a-door adapted to be secured to a refrigerator by 7o hinges and having provision for door fastening means.

Fig. 2 is a perspective view of the member produced by the mold shown in Fig. 1. l

Fig. 2a is a similar view of a member pro- 75 duced by the method'shown by Fig. 1b. A

Fig. 3 is a perspective view of a member Jfor assembly with that shown in Fig. 2 to produce the panel member.

Fig. 3a is a perspective view of a modi- 80 cation of the member shown in Fig. 3, such modified member being designed to coopcrate with the member shown in Fig. 2a.

Fig. 3b is an .enlarged sectional detail of the assembly of Figs, 2a and 3a, partly bro'- S5 ken away.

Fig. 4. is a cross sectional view of the assembledparts of Figs. 2 and. e Fig. 4a is an enlarged sectional detail showing la modification of member shown in Fig. 3. 9o

Fig. 4b is an enlarged sectional detail showing one side portion of the assembly of Fig 4, but with the space between the. members filled with insulating material, and with vthe packing strip in the groove or channelprovided therefor.

Fig. 4c is a modification of the form shown in Figure 4a.

Fig. 5 a section elevation,largely of a A diagrammatic, nature, showing a press for designate two cooperating mold sections having respectively dowel pins 1a and dowel openings 2a for securing proper alinement in the closing of the mold.

Mold section 1 has a rectangular mold clav-Y ity 1b adapted to receive a member' of male part of the mold isso shaped as to propressed sheet-metal whichy is-d'esigned to lform the outer face of the closure or panel member, such member 3 having its edges preferably curved upwardly and inwardly as shown.

, The member 2 of the mold is provided with a cavity entering part of male formation indicated as a whole by the number 2b. This vide outwardly facing substantially vertical walls b spaced from the side walls of the mold cavity and' inwardly facing substantially vertical walls b formed by channels in the under face b2 of said male part, which under face, when themold is closed, is spaced from the bottom of the mold cavity. l

Prior to the closing of the mold, a quanytity of rubber compound 4 is placed therein yupon the'sheet metal facing member, sufcient to completely fill the mold cavity when `the mold is closed. Thereupon the mold member 2 is applied and the mold placed in a press of the customary form and subjected to heat to vulcanize the rubber to the metal facing member and in the shape shown in Fig. l, which it hasnbeen forced to. assume by the closing ofthe mold.

Thel rubber may be an ordinary hard sponge rubber compound or a hard or semi- 'hard rubber compound not ,containing cellforming material, it being understood that hard or semi-hard rubber ar` both regarded bythe trade as hard rubber.

This Vsheet metal member 3 is the part of the panel or closure member which is exposed to the outside of the container and this is usually provided with an enamel or lacquer finishl A.

When the finish is applied -to the sheet beforethe vrubber is combined therewith and is of a brittle nature, 'I prefer to use cushion meansbelow the-sheet metal plate, which cushion means may take the form of an air bag 7, as shown in Fig. la, capable of being inflated by the nipple 7 1r/,extending through the bottomof the lower mold section, or a layer ofv cushion fabric or the like as shown in Fig. 8 at 7g. Y

It will be noticed that the shape of the male part of the mold provides the rubber backing with inwardly facing vertical walls or shoulders 4a and outwardly facing abut- I ment means in the shapeof walls or shoulders 4b of less height and spaced therefrom, forming intervening channels 4c adjacent the four side edges, which are designed to re- Y ceive the edges of an inverted pan-like member 5 of corresponding rectangular shape,

iThis edge is designed to enter the channel (or channels) 4c of the member 4 and be positioned or centered by the abutment means, and the said edge is of such dimensions that, when the members are assembled as shown in Fig. 4, a space is left between the outside edges 5a ofthe member 5 and the walls 4a, in which space is inserted an air cushion packing or sealing gasket a" to cooperate with the corresponding part'of the container, or door jamb in the-case of a refrigerator door.

Prior to the application of the member 5 to the member 4, the surfaces which are to Contact are coated with a suitable rubber cement or a thin layer of soft unvulcanized rubbei' 6 is applied to the bottom of the channel and the assembly then subjected to the necessary heat and pressure to effect a vulcanized or homogeneous joint. Thereby I produce a panel, closure, or door member' of hardened plastic non-conducting material, having an outer sheet metal face and an interior air chamber, all the parts being homogeneously united and all except the said metal face' being'of non-conducting material, and theA heat insulating qualityl being further inceased by the space o r chamber between the` two members.l vulcanization the` heat expands the air and the excess escapes, so that .after vulcanization a partial vacuum exists, which adds to the heat insulating qualities.

' If desired, however, this space,`in the assembling of the members, may be filled with any desired or known-form of non-conducting material, as indicated at 9 in Fig'. 4b.

The hard rubber of which the member` 5 is made will, in the molding process, have a smooth inner surface, but if a surface therefor of enameled or lacquered metal is desired, this may be obtained by securing thereto a metal plate'S, as shown in Fig. '4a. This may he secured by vulcanizing it to therub- In the process of.

conducting ber 5 or it may be first enameled, and to prevent cracking of the enamel, cushion means may be used in the molding similar to that described in connection with Fig. 1a.

Obviously the plate 8 might be extended down over the inclined sides, as shown at A8b in Fig. 4c', in which event it is desirable to make such plate of heat nonmaterial, such for example as Pyralln. f f Y.

Where the panel or closure member is in the shape of a door, means must be provided for the attachment of hinges and the customary latch or closure fastening.

Constructions modified forV this purpose are illustrated in'Figs. 1b, 2a, 3a, and 3b.

In these the rubber 4 of the outer panel member has embedded therein metal blocks 10 having screw holes to engage and securing screws of the hinges or closure `fasteners. This embedding may be accomplished by the use of a mold, as illustrated in Fig. 1b, in

which the block 10 is shown, as supported spaced from finishing plate 3, by pins 16 carried by the lower mold section and having reduced upper ends engaging openings in the block 10, which openings, after removal of the pins, may have screw threads tapped therein for engaging the securing screws.

In said Fig'. 1b I have shown at 7 az' a modiiied form of air bag for cooperating with the iinishing plate 3.

n win be noticed that by the manner in which the blocks or insert's 10 are supported,

they are wholly surrounded by or embedded in the rubber, the upper' mold member being correspondingly recessed, and this produces block-like formations 4d on the inner surface of the rubber layer 4, as will appear from Fig.

2a, in which form I have also .shown lugs 4b as abutment means for positioning the back member instead of flanges 4b'.

In connection -with a front door member such as shown in 2a, I may use a back member such `as shown in Fig. 3a,in which the dish or tray-like member 5 has intergral vertical webs 5b arranged longitudinally and transversely thereof (formed by 'suitably shaping the male member of the mold) which webs form'pockets 50, which may or may not be iilled with insulating maerial, said webs serving materially to strengthen the back member, and also to hold it against collapse during vulcanization. Y

In the forming of this member, recessed Ais generally of a loose nature.

`or closure part of a heat-insulating container,

irrespective of whether such container is intended to retain the enclosed articles in a chilled container ofthe refrigerator or ice r'- type, or a container ofthe' tirelessl cooker type.

In order to permit the airto more readily escapeduring the vulcanizing the upper mold member 2 may be provided with vent openings 20 (Fig. 8) slightly7 enlarged at their upper ends and overlaid'by a sheetof textile materialV 20 on which the upper press memberbears, theair contained'in the mold escaping through said vent openings and the pores in the fabric as-the rubber .compound 4 (shown in said ligure as a spongeA rubber compound, i. e. one containing a blower) expands and iills the moldcavity. In this figure and Figure 9 I-have shown the front member as slightly modified, the margins of the metal platel being reversely curved and I have also shown a modiiied from of upper mold member in which the male lor 4 taposedrubber by the usual-or known methods of vuleanizing rubber to metal.

I find-it desirable in many instances to ex-Y haust the air from between the members prior to .their being homogeneously and hermetically joined, thereby increasing the non-.conductivity, this air exhaustion being practiced irrespective of whether or not a non-conducting iilling material is inserted and being desirable in. connection with such filling which Apparatus suitable for this purpose is il- Iustrated in a conventional manner in Fig. 5.

In this pan-like or-back member 5 is shown "as being supported by a mold' member 1m which is Aprovided with steam cavities to which steam may ber supplied by a flexible pipe 1y from any convenient source (not shown).

This mold member is carried by the movable or piston member 11 of a hydraulic ram, working in a cylinder member 12a carriedby the down ixed press member 12water being admitted to and exhausted from the cylinder or piston chamber through a port-12b by any suitable pipe and valve arrangement not shown, and the piston. being suitably packed to prevent leakage. i

AOpposed to the mold member 1 is the press head1?) tied to the base by vertical rods 14%,v

'which head is provided with a depending flange or rim 13a forming a shallow channel to receive themetalplate 3 with its rubber part 4.

The head is alsoy provided with asteam cavity to which steam is supplied by a pipe system 13b whereby it, like mold member 1w,

may be heated for vulcanizing purposes.

A pipe'15 connected with a port 15a passing through the head and also with any suitable '5 vacuum' producing means, (not shown) enables the member 3 4 to be heldin place by vacuum prior to the elevation of the rain as hereinafter described.

Surrounding the mold 1m and upper portion of the movable member of the ram is a chamber forming member-16 which has a packing y16a vcarried by its upper edge designed to hermetically cooperate withy the down face of the press head, and the opeinng in the bottom of said member through which the piston member of the `ram passes is also provided with packing 16?) to effect a fluid tight 'oint.

Said mem er 16 has depending from the bottom thereof a plurality of piston members 17 which depend into a fluid chamber or chambers18 through suitably packed openings, said chamber or chambers being provided with means for admitting motive fluid thereto or exhausting it therefrom, indicated ronventionally by pipes 19.

' A post passing through the Wall of chamber 16, is connected by flexible pipe 20 with any suitable source of vacuum (not shown).

The member having been placed in the cavity of mold 1w and its edge prepared for vuleanizing, and insulating material having been placed in the member as indicated,

steam is turned on to the mold cavity while the ram is in its lowered position, to heat the mold spfliciently to evaporate any moisture which may be contained in the insulating material.

The panel member 3 4 is placed in the cavity as shown, and held therein by suction (or equivalentl means).

fluid to chamber or chambers 18 until its gasket 16a effects hermetic junction with the down face of the press head whereupon the air from the chamber is evacuated, thus producing a vacuum between the panel members. Ram 11 is then elevated by admitting water or other Vpressure fluid to the ram chamber which forces the ram upward and the coated edges of member 5 into contact with the rubber member 4, whereupon sufficient steam yis turned on to the steam cavities to form a vulcanized joint which will hermetically seal the interior space between the members against access of air and make permanent the vacuum therein,v v

Cold water may be-admittedto the steam and valve arrangements, not'shown, as being Well known to those skilled inthe art, whereby the parts may be cooled in situ if desired prior to opening of thepress and removal of the completed article.

Chamber 16 is then elevatedby admitting water or otherpressure cavities after vulcanization by` suitable pipe Having thus described my invention, what I claim is: v

1. An insulating panel of the character described comprising a front member ofl hard rubber having a facing plate of metal homogeneously united thereto, and a selfsupporting imperforate back member of hard 'a back member of hard rubber spaced from said backing and having inwardly extending marginal flanges homogeneously united to said backing 'within said recess.

`3. An insulating panel of the character described comprising a metal facing plate having marginal flanges, a backing of hard rubber homogeneously united thereto within said flanges, said backing having vertical inwardly facing walls and opposed abutment means, and a substantially dish-shaped selfsupporting member of hard rubber having non-conductive sides with edges seated in the spaces between said walls and abutment means and homogeneously united thereto.

4. An insulating panel of the character described comprising front and back members of hcat-non-conducting material, said back 10 member being of substantially dish-shape'and having its edges homogeneously united to said front member, said front and back memouter surfaces thereof.

5. .An insulating panel of the character described comprising front and back members of heat-non-conducting material, said back member being of substantially dish-shape and having its edges homo eneously united to said front member, said ront and back members having metallic finishing plates homogeneously united therewith and mechanically interlocked therewith at the edges of the finishing plates. t

6. An insulating panel of the character described comprising 'front and back members, said front member having 'Qn its rear side vertical inwardly facing walls and abutment means spaced therefrom, said back member being 'of substantially dish-shape with its edge seated in the space between said -inwardly facing walls and said abutment means, said edge being spaced from said in wardly facing walls, and a cushion packing held in the space between said walls and edge of the dish-shaped member.

7 An insulating panel of the character described comprising a front member of molded plastic heat insulating material, a back mem- 13 ber of similar material of substantially dishsha e having its edge homogeneously united to t e back of said front member, said dishshaped' member having homogeneous nonconductive intersecting webs dividing the v space between said members into a plurality of isolated compartments.

8. An insulating panel of the character described comprising imperforate front and 1c back members, said front. member having on its rear side vertical inwardly facing walls and abutment means spaced therefrom, said back member beinggof substantially dish'- shape with its edge seated 'in the "spacebelxtween said inwardly facing walls and said abutment means, said edge being spaced' from said inwardly facingwal1s,and a cushion packin ,held inthe space between said walls and e of the dish-shaped member, the edges o theback member being homogeneously united to the back of the front member. 9. An -insulating panel of the character described comprising a front member of hard rubber, metallic blocks for attachment of hardware embedded in said hard rubber, and

a substantially dish-shaped member of hard rubber having its edges homogeneously united to said front member. A In testimony whereof, I aix-my signature. RICHARD T. GRIFFITHS.

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